The adaptive cruz/lane keeping system turned off without sufficient warning. I was driving for about 10 miles on the freeway and the lane assistance was working fine. Then at a moment of distraction it turned off right as the road turned. My vehicle continued going straight causing my vehicle to hit another vehicle in the next lane. I believe when active cruz and lane assistance turns off a very loud warning alarm tone should go off. Both vehicles I have driven with these features have minimal warning that the systems stopped working. The flashing light on the instrument cluster is not enough!!! When you have been relying on the vehicle to drive itself for a while, and it suddenly stops working, the warning needs to be much stronger, louder and really alert the driver of the system failure.